Disturbed sleep places older adults at higher risk for frailty, morbidity, and even mortality. Yet nursing home (NH) routines frequently disturb residents? sleep through use of noise and light or efforts, for example, to reduce incontinence. NH residents with Alzheimer?s disease or related dementias (ADRD)?almost two-thirds of long-stay NH residents?are likely to be particularly affected by sleep disturbance. This study tackles these important issues and substantially moves forward goals of the National Plan to Address Alzheimer?s Disease 2018 Update by proposing to implement an evidence-based intervention to improve sleep: a NH frontline staff huddling program known as LOCK. The LOCK program is derived from evidence supporting strengths-based learning, systematic observation, relationship-based teamwork, and efficiency. A LOCK program pilot targeting staff-resident interactions enabled 6 Veterans Health Administration (VA) NHs make meaningful quantitative and qualitative improvements. Preliminary qualitative data from a national VA roll out show that the program is effective when targeting resident clinical outcomes such as pain and pressure ulcers. The program?s methods have also improved clinical care in non-VA NHs. This proposal is therefore an NIH Stage III, real world hybrid efficacy-effectiveness pragmatic trial of the LOCK program for sleep (LOCK sleep program). In non-VA NHs from 3 NH corporations, the study will (1) refine the LOCK program to focus on sleep for residents with ADRD in an R61 phase, (2) test the impact of the LOCK sleep program for NH residents with ADRD in an R33 phase, and (3) evaluate the program?s sustainability. The R61 phase (1 year; n = 3 NHs; 1 NH per corporation) has the following specific aims: (1) Refine the LOCK sleep program train-the-trainer protocol by implementing and pilot-testing it. (2) Refine the research methods to effectively identify eligible NHs and residents, obtain consent, collect primary data from residents and staff, explore staff impressions of additional sleep measurement devices (Fitbits), transfer primary and secondary data to our data center, and merge all data. After successfully completing designated R61 milestones and refining the intervention methods, we will conduct a wedge-design randomized, controlled trial. The R33 phase (4 years; n = 24 NHs; 8 NHs per corporation) has the following specific aims: (1) Implement the LOCK-based sleep program for residents with ADRD using the train-the-trainer model. (2) Estimate impact of the LOCK sleep program on sleep (primary outcome) and on psychotropic medication use, pain and analgesic medication use, and activities of daily living decline (secondary outcomes). (3) Examine factors, using mixed methods, associated with variation in the program?s implementation and its sustainability. This innovative program also has future potential to address other important issues (safety, infection control) and expand to other settings (assisted living, inpatient mental health). The study?s strong team, careful consideration of design challenges, and resulting rigorous, pragmatic approach will ensure success of this promising intervention for NH residents with ADRD.